White Papers

Achieving sufficient capacity to meet the forecast backhaul needs over the next few years will be a major challenge. This white paper describes the technique of Air Division Duplexing (ADD), which makes use of MIMO and spatial multiplexing techniques to achieve simultaneous transmission and reception of data on each carrier frequency, and has been shown to achieve full duplex data rates1 in excess of 1 Gb/s in a 28 MHz channel
allocation2 in the microwave bands.

While LTE-Advanced brings the promise of higher data rates, designing devices for use in LTE-A offer new test challenges. This paper provides an overview of LTE MIMO and carrier aggregation technologies and describes different methodologies for testing these new capabilities including multi-antenna techniques, MIMO spatial multiplexing, beam steering, as well as the different carrier aggregation modes.

Metrigraphics' thin film process is a fundamental technology uniquely suited to the task of making miniature circuits with extremely small and uniform features that have extremely consistent electrical performance throughout. The process also tends to be much faster and less wasteful than subtractive manufacturing methods like chemical etching. That's because only the conductive material needed to define the circuit geometry is being deposited, which results in in a manufacturing process that is more efficient and less wasteful.

This white paper discusses the design of power amplifiers employing Cree GaN HEMTs and NI AWR Design Environment / Microwave Office circuit design software to maximize power-added efficiency (PAE) by optimizing source and load pull at both fundamental and harmonic frequencies. The load-pull scripts within Microwave OfficeÃ?Â are used to find the optimum trade-offs in power gain, efficiency, and stability. The article describes the basis of Class F PA and inverse Class F design F, as well as a new approach called continuous Class F, which enables greater bandwidths to be realized. Several practical design examples are given, including the inspection of voltage and current waveforms for both packaged and bare die transistors in the 10 to 25 watt power range for frequencies up to 2.5 GHz. In addition, the ways in which the Microwave Office load pull wizard can be used to investigate fundamental and harmonic impedances both at the input and output of transistors are discussed.

Innovation that's Open - Introducing OpenRFM. Meeting new government interoperability and affordability requirements in Electronic Warfare and Signals Intelligence, requires innovative approaches in advanced RF/Microwave and digital signal processing. OpenRFM is the first RF/Microwave open system approach that leverages best available commercial-item technology to deliver sophisticated, interoperable sensor processing subsystems to dominate the electromagnetic spectrum. OpenRFM is the better alternative for affordable RF subsystems for our war fighters and allies alike.

For decades, spectrum analyzers have been used to develop and characterize radar and electronic (EW) warfare systems. However, traditional swept measurements are rapidly becoming insufficient because most modern radar systems are adaptive. Learn about methods for monitoring EW scenarios, identifying unwanted events in the transmitted waveform, and accurately measuring found signals.Ã?Â

A generation ago, easy-to-use GaAs HBT based RF Gain Blocks changed the way RF engineers designed small signal amplifiers. That same evolution is now arriving in GaN technology with simple broadband solutions to medium power requirements in the 5 to 25 Watt range. This power range appears in a wide array of customer requirements, from output stages in broadband land-mobile and military handheld radios, small cell linear finals, to drivers in larger military, EW, and infrastructure power amplifiers. Entering the realm of power amplifiers though obviously brings new requirements and challenges, among them cost, size, power efficiency, and difficult thermal limitations that drive their electrical and package design. This paper will review conventional solutions, explore the tradeoffs between discrete and monolithic MMICs, and highlight the unique benefits of this new hybrid SMT solution.

When designing printed circuit boards launches for coaxial test connectors, there are a number of aspects to consider in order to get the clearest picture of the intended device under test. Learn a relatively simple approach to modeling back-drilled vias and a rough "rule of thumb" to modeling them without electrical modeling tools.